In control and protection systems of process plants, for example in the chemical industry, the pharmaceutical industry or the oil/gas industry, automation systems are regularly used which in the event of improper operating procedures of the process plant, such as pressure drops, increases in temperature or the like, generate a large number of items of alarm information and pass them to a plant operator. In certain situations, for example when shutting down a process plant, this can lead to a flood of system-generated alarms which the operator can no longer control or command, and this can result in possibly serious accidents.
In control and protection systems of process plants, international associations, such as NAMUR (www.namur.de) therefore demand solutions that are capable of activating or deactivating specific alarms as function of the plant state and the combination of pending alarms (what is known as dynamic alarm processing). This should lead to a reduction in alarm occurrence and therewith allow the plant safety to be generally restored.
From the prior art, rigid, i.e. non-dynamic filtering of alarms is known in this connection in which specific filtering rules have to be explicitly indicated for each individual alarm that may be generated. Process-induced alarm states (sub-) plant states are not recognized by the system or are not dynamically taken into account.
Other known solutions allow filtering of alarms directly at the source of the alarm, i.e. at process level, by installation of an appropriate logic system. With a solution of this kind one particular disadvantage is that it is no longer possible to trace the fault. Alarms filtered at the source cannot be archived and are therefore unavailable for subsequent analyses or random evaluations at process control level.
Furthermore, what are known as alarm management systems in the form of designated, independent systems for alarm handling of process plants are known. Since they operate independently and irrespective of the process plant control system, they demand appropriate additional attentiveness on the part of the plant operator. Moreover, independent systems of this kind do not provide the convenience of a solution integrated in the plant operation nor are they capable of automatically taking account of changes in the plant control and protection system since, in particular, there is separate data storage and separate engineering.